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CONCORD, N.H. - The remnants of Tropical Storm Irene quickly passed through New Hampshire, but might have left lasting changes to Lake Sunapee, one of its largest lakes.

The freshwater lake is one of about 30 around the world being monitored by a network of scientists, ecologists, and engineers. A buoy set in the lake in 2007 monitors temperature, wind direction and speed, and oxygen levels every 10 minutes. When Irene passed by in August, the buoy detected a lot of water mixing within the lake. Scientists want to know to what degree it affected lake temperatures and plant life.

“It’s like a big bathtub, and the water starts sloshing around, and it had been at different temperatures; it was warmer on the top and colder as you went down,’’ said Kathleen Weathers, a scientist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y., and a volunteer researcher for the Lake Sunapee Protective Association. “The first thing that it did was to mix it all.’’

Irene, first a hurricane and later a tropical storm, doused the East Coast in August after a wet summer in most of the Northeast. Days later, the region was soaked by Tropical Storm Lee.

Weathers and others will be discussing how lakes respond to hurricanes and other natural events at a weeklong international conference in Newbury starting Monday. More than 100 scientists from 24 countries will discuss how to keep lakes healthy amid population growth. Previous conferences were held in Israel, Brazil, and China.

The buoy was provided by the Global Lake Ecological Network, a volunteer group, and was launched by the Lake Sunapee Protective Association. .

Weathers said the technology has allowed scientists to look at lakes in ways they never could before. “We would go out and take a sample once a month or once a week or even once a day and not know what the lake was doing in between - how it was ‘breathing,’ if you will - and functioning in between those times.

“Now, it’s like an EKG; it’s like monitoring some part of human health,’’ she said. During the summer, for example, the data shows higher dissolved oxygen levels during the day, indicating that plants in the lake are going through photosynthesis, then slowing down at night.

Scientists also are hoping that data from the buoy can help provide more clues about algae blooms that have been occurring in Lake Sunapee and in others.

“They’re trying to understand why it’s showing up now and what its life cycle is,’’ said June Fichter, executive director of the protective association. “It’s a concern. You don’t want them to get too many blooms, because that would affect the health of the lake,’’ which is a source of drinking water.